US2478179A

US2478179A - Piston

Info

Publication number: US2478179A
Application number: US754144A
Authority: US
Inventors: Joseph A Brockmeyer
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-06-12
Filing date: 1947-06-12
Publication date: 1949-08-09
Anticipated expiration: 1966-08-09

Description

J. M. @RCKMYEW PISTON 2 Sheets-Sham E Film1 Jun@ l2@ 190W INVENTOR. JA. rocfmeJ/@r' BY a /1 TTOQ/VEY Patented Aug. 9, 1949 UNITED STATES PATENT OFFICE 6 Claims.

This invention relates to a piston of the type used in internal combustion engines, pumps and the like, and the main object of the invention is to produce an improved piston of this type.

A further object of the invention is to produce an improved construction in which the piston is provided with a detachable head provided with parts ior receiving conventional piston rings so that, when the rings wear out, they may 'oe replaced with new ones by removing the detachable head but without removing the piston itself from the cylinder.

it still iurther object oi the invention is to produce a piston construction in which the heat dissipation is improved thus making for cooler operation, less breakdown oi the lubricant, and less wear.

il. still further object is to produce an improved construction in which the upper portion of the piston may be made lighter or of a relatively smaller vertical cross-sectional thickness, as viewed in the drawings, without sacrificing its load capacity.

A stili further object is to improve the manner in which the detachable piston head is secured to the piston body.

A still further object is to produce an improved construction whereby, when the worn out rings are replaced a new piston lit is achieved and whereby this may be done at a relatively low cost in replacement parts and in effort.

These and other objects are attained by my invention as set forth in the following specification and as illustrated in the accompanying drawings in. which Fig. l is an exploded view of a piston embodying my invention.

Fig. 2 is a vertical sectional view of the piston shown assembled.

Fig. 3 is a top plan view of Fig. 2.

Fig. 4 is a side elevational view of the piston shown in Figs. l to 3.

Fig. 5 is a vertical sectional view showing an other embodiment of my invention.

Fig. 6 is a view similar to Fig. 5 showing a slightly modiiied structure.

Fig. 7 is a top plan view of a clamping ring used in securing the detachable head to the piston body in the embodiment of the invention shown in Figs. l. to 4.

Fig. 8 is a top plan view of a clamping ring used in securing the detachable head to the piston body in the embodiment of the invention shown in Figs. 5 and 6.

Referring to Figs. 1 to 4, there is shown a plston having a cylindrical lower skirt portion I il, and a frusto-conical reduced, upper head portion l2, the portions i0 and i2 being connected by a horizontal portion forming a shoulder it. The piston construction also includes a sleeve it having exterior grooves it for receiving conventional split rings til, the sleeve being internally tapered for a snug iit over the truste-conical portion il.

Near its top surface 22, the upper portion il is provided with a peripheral groove lt for receiving the resilient split clamping ring 26 of Fig. 7. The ring 2t is so made that, when free, it tends to constrict. The juxtaposed ends of the rings 2t are provided with holes or recesses t@ adaped to be engaged-by an expanding type spanner wrench for applying or removing the ring. Thus, when it is desired to apply or remove the clamping ring, the points of the jaws of the Spanner wrench are engaged in the recesses 28 and the handles of the wrench are moved in a direction to cause the jaws of the wrench to move apart, thus expanding the clamping ring until it clears the groove 2l. The clamping ring may now be removed from, or placed in the groove, as the case may be.

The height of the sleeve i6, that is, the distance between broken lines A and B, and the height of the tapered upper portion I2, that is, the distance between the broken lines C and D, in Fig. 1, are such, in relation to the thickness of the clamping ring and the height of the groove 24 that, when the sleeve i6 is slipped over the tapered portion I2 and the ring 26 is placed in the groove 24, as shown in Fig. 2, the sleeve will be pressed downwardly against the shoulder i4 and against the tapered surface of the portion i2 so that it is held rmly in position against rotation relative to the piston. By this means, the oil holes 30 in the sleeve i6 will be maintained in proper registration with the holes 32 in the piston portion l2. It will be understood that the upper surface 34 of the sleeve i6 and the upper surface 22 of the tapered portion I2 of the piston will be suitably indexed, as at 33, so as to insure initial alignment of the holes 30 in the of the upper surface 22 l' sleeve, with the holes 32 in the piston portion I2 during the assembly of the piston.

When it is desired to renew the piston rings, the piston is moved to its uppermost position, the clamping 26 is removed, and the piston is lowered. When this is done the sleeve I6 is detached from the portion I2 oi' the piston and remains in the upper portion of the cylinder from which it can be readily removed. If the sleeve I6 should stick to the top oi the piston and should move down with it, the piston is raised up again, and the sleeve I6 is tapped with a wooden mallet, or the like, to break the bond between it and the top of the piston and the piston is again lowered so as to leave the sleeve I6 at the upper end of the cylinder. In practice, I nd that this happens only infrequently. When the sleeve has been removed, the piston is again raised and a new sleeve I6 having new rings 20 is then forced onto the tapered piston portion I2 and is clamped in position by the ring 26. While it is possible merely to replace the worn-out rings, I found, in practice, that it is preferable to use a new sleeve I6 equipped with new rings 20 so as to provide a new piston fit. This is due to the fact that when the grooves I8 wear somewhat, new rings placed in these grooves will be somewhat loosely seated y, and will, therefore, permit leakage and will cause wear, particularly along the upper and. lower edges of the rings.

The taper of the upper piston portion I2 and of the sleeve I6 is such that the area of the upper surface 34 of the sleeve I6 exceeds the area of the tapered piston portion I2. By this arrangement, the surface 22 of the portion I2 is subjected to a smaller portion of the force of the explosion while the surface 34 of the sleeve I6 receives a larger portion of the force of the explosion. Because of this arrangement, the flat top of the upper piston portion can `be made thinner, in vertical cross section, without danger of breaking or of caving in. Because the sleeve I6 is supported on the relatively large surface area of the frusto conical portion I2, which has the relatively thick wall 35, it can withstand the major portion of the force of the explosion to which it is subjected. The taper of the portion I2 and of the sleeve I6 is also such as to produce a wedging frictional engagement of an order suicient to prevent rotation of the sleeve relative to the piston when the clamping ring 26 is in position, without the need of screws or the like for securing the sleeve to the piston.

Furthermore, because the top of the tapered portion is of a relatively small diameter, it can be made of a thinner vertical cross section than would be otherwise possible.

Bymaking the area of the surface 34 of the sleeve I6 bigger than the area of the top 22 of the piston, the sleeve will absorb a larger amount of heat than the piston and, because the sleeve I6 can dissipate its heat more rapidly than the piston can, generally cooler operation will result, thus reducing wear and tear on the contracting moving parts.

In Figs. and 6, there is shown a structure which is identical with that of Figs. 1 and 2 except that the height of the sleeve is equal to the height of the tapered portion I2, so that the surface 34 is flush with the surface 22. To produce this structure, the upper surface 34 of the sleeve I6 is counter-bored, as at 40, to provide room for application and removal of a clamping ring.

In the structure of Fig. 5, I prefer to use a clamping ring 44, which is clearly shown in Fis. 8. This ring is made of two parts 4l and 46 which are secured in assembled position by interlocking end lugs and recesses 41. This type of ring does not need the room needed for applyins and removing the ring 26, and no special wrench' is needed. The parts 45 and 48 can be forced into position manually with the aid of a pair o! pliers, or the like, and can be disengaged by means of a screw driver or the like.

Fig. 6 also shows that in the structure oi. Figs. 2130225 the top of the piston can be concaved, as a It will thus be seen that, by providing the shoulder I4, the grooves 24 or 40, the clamping ring 26 and the separable sleeve I6, and by tapering the upper portion I2 of the piston and the sleeve I 6 to substantially the proportions shown in the drawings, a light, strong and cool-operating piston is produced. It will also be seen that the sleeve I6 and the ring 20 carried thereby may be removed and installed as a unit and that the removal of the sleeve I6 and the installation of a new sleeve, equipped with new rings, will have the same effect as the installation of a complete new piston.

Having described my invention, what I claim is:

l. A piston comprising a lower cylindrical por tion, an upper, frusto-conical portion, a sleeve having an internal, frusto-conical bore adapted to t over said upper, frusto-conical portion, with at least the inner portion of the top wall of said sleeve disposed below the top wall of said frustoconical portion,said sleeve also having an outer cylindrical surface adapted to form a continuation of the cylindrical surface of the lower portion of the piston, and means for detachably securing said sleeve to said frusto-conical portion, said means including a groove formed in said frusto-conical portion immediately below the top wall thereof, with the bottom wall of said groove substantially flush with the inner adjacent portion of the top of said sleeve, and a clamping means engaging said groove and said inner adr jacent portion of the top of said sleeve to prevent vertical movement of said sleeve relative to said frusto-conical portion.

2. The structure recited in claim 1 in which said clampingmeans is a split ring and in which the inner portion of said ring engages said groove and the outer portion of said ring overlies the inner adjacent portion of the top of said sleeve.

3. The structure recited in claim 1 in which the base of said upper frusta-conical portion has a diameter smaller than the diameter of the lower cylindrical portion of the piston whereby a shoulder is formed at a right angle to the vertical axis of the piston.

4. The structure recited in claim 1 in which the outer portion of the top of the sleeve, which is not engaged by said clamping means, is flush with the top of said upper frusto-conical portion of the piston.

5. A piston comprising a lower skirt portion, an upper frusto-conical head portion, a sleeve having a tapered internal bore adapted to t over said head portion and having an external surface adapted to form a continuation of the surface "of said skirt portion, the taper of said head portion being such that the area of the top surface of said head portion is less than the area of the top surface of said sleeve, and means for securing said sleeve to said head portion.

6. A piston comprising a lower skirt portion, an upper. hollow head portion formed of a irustoamarre 5 conical wall structure and end wall at the smaller REFERENCES CITED end of said frusto-conical wall structure, an an- The following referentes are of record in the nular sleeve having an external surface adapted me of this patent; to form a continuation of the external surface TES of said skirt portion and having a tapered bore s UNITED STA PATENTS JOSEPH A. BR()CK1ME1YER 2,369,906 MOOle Feb. 20, 1945